Device and method for an exhaust system of a motor vehicle

ABSTRACT

A device for an exhaust system of a motor vehicle includes baffle wall, a passage, and a body having a sidewall with an exhaust conduit extending therethrough. The baffle wall has a bore in fluid communication with the exhaust conduit. The baffle wall extends from the sidewall and into the exhaust conduit for directing the flow of exhaust gas through the bore and increasing a speed of the flow of the exhaust gas. The passage extends through the sidewall of the body for fluid communication between the bore and an ambient environment. As such, the increased speed of the flow of the exhaust reduces the pressure and creates a venturi for drawing cool ambient gas into the flow of the hot exhaust gas. In addition to the venturi, the bore and the passage collectively generate a desirable engine exhaust sound when the flow of the exhaust gas passes therethrough.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser. No. 61/811,937 filed Apr. 15, 2013, the disclosure of which is expressly incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present invention relates generally to a device and method for an exhaust system, and more particularly, to a device and method for discharging engine exhaust from an exhaust system of a motor vehicle.

BACKGROUND

Motor vehicles, such as automobiles, motorcycles, scooters, or any other vehicle for transport, traditionally employ an internal combustion engine for converting chemical energy into thermal energy. In turn, the engine converts the thermal energy into mechanical energy for generating the power used while operating the vehicle. Of course, the production of mechanical energy via the internal combustion engine also produces exhaust gas that must be discharged from the engine. Traditionally, the thermal energy created by the engine generates significant heat, a portion of which passes from the engine through relatively high temperature exhaust gas. For example, a diesel internal combustion engine may produce exhaust gas temperatures well over 1000° F. Thus, exhaust systems have been developed for safely maintaining, treating, and discharging high temperature exhaust gas to an ambient environment.

While exhaust systems capable of withstanding high exhaust gas temperatures are well-known in the motor vehicle industry, it is also well known that vehicle exhaust systems must be carefully designed and manufactured of metals and alloys having material properties suitable at these high operating temperatures. However, metals and alloys having favorable high temperature material properties are typically more expensive and more difficult to procure than more traditional metals and alloys. Furthermore, increased environmental concerns may require relatively high combustion temperatures for various after treatment systems, which only reinforces the likelihood of high exhaust gas temperatures entering the exhaust system. For this reason, manufacturers of present exhaust systems often use high cost materials along the majority of the exhaust system or risk premature failure during use.

In addition, many vehicle owners specifically choose vehicle engine and exhaust system components for increased performance during use and may even prefer exhaust systems capable of generating enhanced or augmented engine sound produced by the exhaust gas. For this reason, after market components for generating or augmenting engine sound are common throughout the motor vehicle industry. For example, a portion of the exhaust system may be used to increase overall volume and resonance to make a relatively small engine, such as a scooter engine, sound like a larger engine, such as a motorcycle engine. However, due to high exhaust gas temperatures, these sound generation portions of the exhaust system may also be manufactured from relatively expensive metals and alloys.

Accordingly, there is a need for a device and method for use with a motor vehicle, such as an exhaust system, that addresses present challenges and characteristics such as those discussed above.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below serve to explain the invention.

FIG. 1 is a schematic perspective view of a motor vehicle including an exhaust system according to an exemplary embodiment.

FIG. 2 is a perspective view of one exemplary embodiment of a tip exhaust device connected to a tail pipe as shown in FIG. 1.

FIG. 3 is an enlarged perspective view of the tip exhaust device shown in FIG. 2.

FIG. 4 is a cross-section view of FIG. 3 taken along section line 4-4.

FIG. 5 is a cross-section view of another exemplary embodiment of a device shown in FIG. 1 taken along section line 5-5.

DETAILED DESCRIPTION

With reference to FIG. 1, an embodiment of a motor vehicle 10 including an exhaust system 12 for cooling high temperature exhaust gas, particularly with respect to generating a desirable engine noise, includes an internal combustion engine (not shown) operable for generating power and moving the motor vehicle 10. The engine (not shown) generates a pressurized exhaust gas and engine exhaust sound that flows into the exhaust system 12, which, in one embodiment, includes an inline exhaust device 14 and a tip exhaust device 15 for cooling the exhaust gas and generating a desirable exhaust sound. The exemplary exhaust system 12 may also include an exhaust manifold 16, a catalytic converter 18, a resonator 20, and a muffler 22 all fluidly connected in series by portions of an exhaust pipe 24, 26, 28, 30. More particularly, the portions of the exhaust pipe include a “Y” pipe 24, a medial pipe 26, an upstream pipe 28, a downstream pipe 30, and a tail pipe 32, all fluidly connected in series to various components of the exhaust system 12. For example, the exhaust manifold 16 is directly connected to the engine (not shown). The “Y” pipe 26 fluidly connects the exhaust manifold 16 to the catalytic converter 18, which converts combustion byproducts into other, less harmful molecules. From the catalytic converter 18, the exhaust gas moves through the medial pipe 26 to the fluidly connected resonator 20. The resonator 20 is generally hollow and resonates under the influence of exhaust gas and sound and may be tuned for damping portions of the engine exhaust sound while enhancing other portions of the exhaust sound for use downstream in the exhaust system 12. The exhaust gas and tuned sound then move through an upstream pipe 28 fluidly connected to the inline exhaust device 14.

Furthermore, as will be discussed more fully below, the exhaust gas and tuned sound respectively cool and change while operatively passing through the inline exhaust device 14 to the fluidly connected downstream pipe 30. The downstream pipe 30 fluidly connects to the muffler 22 for reducing the overall engine exhaust sound. Finally, the muffler 22 fluidly connects to the tail pipe 32. The tip exhaust device 15 fluidly connects to an end 34 of the tail pipe 32 for receiving and cooling exhaust gas and generating a final desirable exhaust sound for discharge into an ambient environment 35, as described below in greater detail. While the above describes an exemplary embodiment, it will be appreciated that the motor vehicle 10 and exhaust system 12 is not intended to be limited to an automobile and traditional automobile exhaust system as described above. Rather, the inline exhaust device 14 and the tip exhaust device 15 may be fluidly connected to an exhaust pipe for receiving exhaust gas from a broad range of internal combustion engine vehicles. For example, it is contemplated that the inline exhaust device 14 and tip exhaust device 15 may be used with, but not necessarily limited to, the automobile, a truck, a scooter, or a motorcycle. Similarly, the inline exhaust device 14 and the tip exhaust device 15 may be fluidly connected at a broad range of positions along the exhaust system downstream of the engine (not shown) in accordance with the invention described herein. Also, it will be appreciated that one or more of the inline exhaust devices 14 may be connected in series or parallel via the exhaust pipe for further cooling the exhaust gas or augmenting the engine exhaust sound. Furthermore, the inline exhaust device 14 and the tip exhaust device 15 may be used together, as shown in FIG. 1, or separately. On one hand, one or more inline exhaust devices 14 may be fluidly connected within an exhaust system without the tip exhaust device 15. On the other hand, the tip exhaust device 15 may be fluidly connected to an exhaust system without the inline exhaust device 14. Also, in the event that an exhaust system includes two or more tail pipes, each of the tail pipes may be connected with one of the tip exhaust devices 15 such that a plurality of the tip exhaust device 15 may be used. Thus, the particular use of the inline exhaust device 14 and/or tip exhaust device 15 may be customized as desirable by a manufacturer and/or individual vehicle owners to achieve a desired outcome.

With respect to FIGS. 2-4, the exemplary tail pipe 32 is operatively connected to the tip exhaust device 15. In an exemplary embodiment, the tip exhaust device 15 generally includes a body 36 having a proximal end portion 38 and a distal end portion 40. The body 36 is generally cylindrical in shape and further includes an annular sidewall 42 defining an exhaust passageway or conduit 44 extending through the proximal end portion 38 for receiving a flow of exhaust gas, indicated by arrows 46. To this end, the proximal end portion 38 generally includes an inlet 48 extending into an outer bore 50 that transitions distally to a shoulder 51 of an inner bore 52. The outer bore 50 is generally sized to receive the end 34 of the tail pipe 32. A threaded hole 54 extends through the sidewall 42 at the outer bore 50 and receives a threaded fastener 56 for mounting the tip exhaust device 15 to the tail pipe 32. When the end 34 of the tail pipe 32 inserts into the outer bore 50 and engages against the shoulder 51, the threaded fastener 56 may be tightened down onto the tail pipe 32 to secure the body 36 onto the tail pipe 32. When so coupled, the tail pipe 32 fluidly communicates the flow of exhaust gas from the inlet 48 and into the exhaust conduit 44 at the inner bore 52.

The tip exhaust device 15 further includes a baffle wall 58 positioned adjacent the distal end portion 40 of the body 36. The baffle wall 58 extends generally radially inward from the sidewall 42 and into the exhaust conduit 44 for blocking and directing the flow of the exhaust gas. The baffle wall 58 also includes at least one bore 60 extending therethrough so as to be in fluid communication with the exhaust conduit 44 and the ambient environment. As such, the baffle wall 58 directs the flow of the exhaust gas from the exhaust conduit 44 and through at least one bore 60. According to an exemplary embodiment, the bore 60 defines a bore central axis positioned generally parallel to the direction of the flow of the exhaust gas moving in a direction defined by a central axis of the exhaust conduit 44. The baffle wall 58 is also generally transverse to the conduit central axis and direction of the flow of the exhaust gas. However, it will be appreciated that the alignment of the baffle wall 58 and bore 60 may vary relative to the direction of the flow of the exhaust gas in accordance with the invention described herein. Preferably, the baffle wall 58 includes a plurality of the bores 60 extending therethrough, whereas each of the bores 60 may be circumferentially positioned about the baffle wall 58 adjacent to the sidewall 42 (e.g., adjacent the periphery of the baffle wall). The purpose of positioning the bores 60 adjacent the sidewall 42 will be described below. According to an exemplary embodiment, the baffle wall 58 includes six bores 60 symmetrically positioned about the baffle wall 58, which is also generally annular in shape. As shown in FIGS. 2-4, the baffle wall 58 may also be generally concave downstream of the flow of the exhaust gas 46. However, other arrangements, such as a flat planar baffle wall may also be possible.

Furthermore, at least one passage 62 extends through the sidewall 42 for fluidly communicating an ambient gas, indicated by arrows 64, from the ambient environment 35 and into the at least one bore 60. Preferably, the sidewall 42 includes a plurality of passages 62 such that each passage 62 extends into one of the respective bores 60. Thus, according to an exemplary embodiment, the sidewall 42 may include six annularly positioned passages 62 that are symmetrically positioned about the body 36 for alignment with a respective one of the six bores 60 through the baffle wall. More particularly, each passage 62 extends from an ambient port 66 located in the outer surface of the sidewall 42 to an exhaust port 68 positioned in the inner surface of the bore 60. The ambient port 66 on the sidewall 42 is in fluid communication with the ambient environment 35, whereas the exhaust port 68 is in fluid communication with the exhaust gas passing through the bore 60. According to an exemplary embodiment, the exhaust port 68 is distally positioned from the ambient port 66 such that the passage 62 has a passage central axis that extends at an angle θ from the bore central axis. More particularly, the angle θ may be between 0 and 90 degrees. According to an exemplary embodiment, the angle θ is from about 10 degrees to about 25 degrees. More particularly, the angle θ is about 18 degrees and the position of the exhaust port 68 is entirely within the bore 60.

Given the similarities between the tip exhaust device 15 and the inline exhaust device 14 shown in FIG. 5, the effect of the exhaust devices 14, 15 on the flow of the exhaust gas through the exhaust system 12 will be described collectively below following the description of the inline exhaust device 14.

FIG. 5 shows an exemplary embodiment of the inline exhaust device 14 in which like numbers indicate like features described above. In this respect, the inline exhaust device 14 functions similarly to the tip exhaust device 15; however, rather than being secured to the end 34 of the tail pipe 32 as in FIG. 1, the inline exhaust device 14 is configured for fluid communication between two components of the exhaust system 12 (e.g., the exhaust device is intermediate the engine and the end of the exhaust system). However, to gain the full benefit of the exhaust device 14, it is preferable that the exhaust device be positioned more adjacent the engine. In addition to that described above for tip exhaust device 15, the body 36′ of the inline exhaust device 14 includes a coupling end portion 70 distally positioned from the baffle wall 58 for securing to a downstream portion of the exhaust system 12. To this end, the coupling end portion 70 generally includes an outlet 72 extending into an outer bore 50′ that transitions proximally to a shoulder 51′ of an inner bore 52′. The outer bore 50′ and the outer bore 50 are sized to receive the upstream and downstream pipes 30, 28, respectively. The threaded hole 54 extends through a sidewall 42′ at the outer bore 50′ and receives the threaded fastener 56 (e.g., similar to that shown in FIG. 2). When the upstream and downstream pipes 28, 30 insert into the outer bore 50 and outer bore 50′ against respective shoulders 51, 51′, the threaded fasteners 56 tighten down onto the upstream and downstream pipes 28, 30 to secure the body 36′ thereon. Thus, the tail pipe 32 fluidly communicates the flow of exhaust gas from the inlet 48, into the exhaust conduit 44, and through the outlet 72.

Operation of the exhaust devices 14, 15 will now be described. With respect to embodiments of the tip exhaust device 15 and the inline exhaust device 14 shown in FIGS. 4 and 5, each of the bores 60 and passages 62 collectively generate a venturi effect for drawing cooler ambient gas, such as ambient air, into the relatively hot flow of exhaust gas for cooling the exhaust gas during use. More particularly, the flow of the relatively hot exhaust gas 46 moves under the influence of a back pressure from the engine (not shown) at a first speed and deflects at the baffle wall 58 so as to flow through each of the bores 60. While moving into and through the bores 60, the flow of the hot exhaust gas 46 increases in speed to a second speed, because a collective cross-sectional area of the one or more bores 60 is less than a collective cross-sectional area of the exhaust conduit 44 (e.g., an area of reduced flow). In turn, the increase in speed reduces the pressure of the exhaust gas flowing through the bores 60 (indicated by arrows 74) to a relatively low pressure, according to Bernoulli's principles.

More particularly, the low pressure of the flow of the exhaust gas 74 through the bores 60 is below an ambient pressure of the ambient environment 35. The low pressure of the flow of the exhaust gas 74 then effectively generates suction, which draws cooler ambient gas from the ambient environment 35, through the passage 62, and into the bore 60. The cooler ambient gas is indicated herein by arrows 76. Finally, the cooler ambient gas mixes with the hot exhaust gas to create a mixed exhaust gas having a final temperature lower than the flow of the hot exhaust gas entering either exhaust device 14, 15. The mixed exhaust gas is indicated herein by arrows 78. As described above, the inline exhaust device 14 and tip exhaust device 15 may be used individually or in any combination. In this respect, it will be appreciated that the exhaust gas may already be mixed with ambient gas to some extent by the combination of upstream and downstream exhaust devices 14, 15. Thus, the distinction between the particular make-up of exhaust gas and mixed exhaust gas is merely exemplary and not intended to limit the invention. Furthermore, it will be appreciated that the exhaust gas, ambient gas, and the mixed gas may include portions of gas that may condense into fluids while cooling. Any fluids which accumulate as a product of combustion and condensation are contemplated herein and are not intended to limit the invention described herein.

An exemplary embodiment of the tip exhaust device 15 and the inline exhaust device 14 preferably includes the plurality of bores 60 and passages 62 as described above. Thus, the flow of exhaust gas 46 preferably divides into a plurality of flows of exhaust gas 74 rather than just a singular flow of exhaust gas. As such, each venturi described above more effectively mixes and cools each respective flow of exhaust gas 74 with each flow of ambient gas 76 than singular flows of exhaust through the baffle wall 58. Each of the bores 60 is preferably positioned adjacent to the sidewall 42 for increasing the speed of the flow of the exhaust gas 74 adjacent to the sidewall 42. Often times, flow speed adjacent to a wall tends to be slower, and less likely to mix with surrounding gases. Thus, by increasing the exhaust gas 74 adjacent to the sidewall 42, the placement of the bores 60 encourages more mixing with the ambient gas 64 and increased cooling effect.

In addition to cooling exhaust gas, the bore 60 and passage 62 also collectively generate a desirable exhaust sound. Specifically, the venturi created at the bore 60 and passage 62 relate to a resonance within the tip exhaust device 15 and the inline exhaust device 14. The resonance augments the existing exhaust sound when the flow of the exhaust gas is directed through the bores while the ambient gas, simultaneously, draws into each of the bores 60. Again, the desirable exhaust sound may be generated with only one of the exhaust device 14, 15 or may be selectively tuned with multiple exhaust devices 14, 15 in combination with other components of the exhaust system 12 (see FIG. 1).

By virtue of the venturi effect cooling the flow of the exhaust gas, portions of the exhaust system 12 downstream of the inline exhaust device 14 may be manufactured from cheaper materials with less weight. For example, common exhaust materials include mild steel, stainless steel, or titanium, which require tradeoffs, readily appreciated by one of ordinary skill in the art, between relatively high cost, aesthetic appearance, and weight. However, by reducing the temperature of the flow of the exhaust gas as described above, the downstream portions may be manufactured of aluminum, which may be cheaper, lighter, and more aesthetically appealing than more common exhaust system materials.

In other words, cool ambient gas is mixed with the hot exhaust gas flowing through the exhaust devices 14, 15. The addition of this cool gas is configured to also cool the exhaust device 14, 15 itself, such that it may operate at a relatively lower temperature and cool the overall temperature of the exhaust gas. Accordingly, the mixed gas (e.g., exhaust gas from the engine and ambient gas) flowing downstream of the exhaust device 14, 15 generally has a lower temperature.

For this reason, the tip exhaust device 15 and the inline exhaust device 14 may also be manufactured from cost effective aluminum. For example, an exemplary embodiment of the tip exhaust device 15 is manufactured as described above from a unitary piece of AA6061-T5 aluminum. As such, the inline and tip exhaust devices 14, 15 both may be used to generate a desirable exhaust sound while simultaneously cooling the flow of the exhaust gas.

While the present invention has been illustrated by the description of one or more embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method and illustrative examples shown and described. Accordingly, departures may be from such details without departing from the scope of the general inventive concept. 

What is claimed is:
 1. A device for an exhaust system of a motor vehicle, the exhaust system including an exhaust pipe for receiving a flow of exhaust gas from an engine of the motor vehicle and discharging the flow of exhaust gas into an ambient environment, the device comprising; a body having a sidewall and an exhaust conduit extending therethrough; a baffle wall having at least one bore, the at least one bore in fluid communication with the exhaust conduit extending therethrough for increasing a speed of the flow of exhaust gas through the bore; and a passage extending through the sidewall of the body from the ambient environment to the bore for fluid communication therebetween, wherein the bore and the passage are configured to generate a venturi and draw cooler ambient gas through the passage and into the bore.
 2. The device of claim 1 wherein the baffle wall and the passage are collectively configured to generate a desirable exhaust sound when simultaneously directing the flow of the exhaust gas through the bore and drawing ambient gas into the bore via the venturi.
 3. The device of claim 1 wherein the passage extends from an ambient port in fluid communication with the ambient gas to an exhaust port in fluid communication with the bore in the baffle wall, and the exhaust port is distally positioned from the ambient port such that the ambient gas moves into the exhaust gas at an angle between 0 and 90 degrees from a direction of the flow of the exhaust gas.
 4. The device of claim 1 further comprising: a plurality of the bores extending through the baffle wall and in fluid communication with the exhaust conduit for directing the flow of exhaust gas through each of the bores and increasing the speed of the flow of exhaust gas through each of the bores; and a plurality of the passages extending through the sidewall of the body from the ambient environment, each of the passages extending to respective bores in the baffle wall for fluid communication therebetween.
 5. The device of claim 4 wherein the plurality of bores are positioned adjacent to the sidewall of the body.
 6. The device of claim 4 wherein the plurality of bores and the plurality of passages are symmetrically and radially positioned about the baffle wall and sidewall, respectively.
 7. The device of claim 1 wherein the body has an end portion for fluidly connecting to a portion of the exhaust system.
 8. The device of claim 7 wherein the body has another end portion for fluidly connecting to a remaining portion of the exhaust system.
 9. A device for an exhaust system of a motor vehicle, the exhaust system including an exhaust pipe for receiving a flow of exhaust gas from an engine of the motor vehicle and discharging the flow of exhaust gas into an ambient environment, the device comprising; a body having a sidewall and an exhaust conduit extending therethrough, the body having a distal end portion and a proximal end portion, the proximal end portion having an inlet in fluid communication with the exhaust conduit and configured for connecting to the exhaust pipe to receive the flow of exhaust gas; a baffle wall having a bore in fluid communication with the exhaust conduit extending therethrough, the baffle wall extending from the sidewall and into the exhaust conduit at the distal end portion for directing the flow of exhaust gas through the bore and increasing a speed of the flow of exhaust gas through the bore; and a passage extending through the sidewall of the body from the ambient environment to the bore in the baffle wall for fluid communication therebetween, wherein the bore and the passage are configured to generate a venturi and draw cooler ambient gas through the passage and into the bore from the ambient environment for introducing cooler ambient gas into the flow of the exhaust gas for reducing a temperature of the flow of the exhaust gas through a remaining portion of the exhaust system.
 10. The device of claim 9 wherein the baffle wall and the passage are collectively configured to generate a desirable exhaust sound when simultaneously directing the flow of the exhaust gas through the bore and drawing ambient gas into the bore via the venturi.
 11. The device of claim 9 wherein the passage extends from an ambient port in fluid communication with the ambient gas to an exhaust port in fluid communication with the bore in the baffle wall, and the exhaust port is distally positioned from the ambient port such that the ambient gas moves into the exhaust gas at an angle between 0 and 90 degrees from a direction of the flow of the exhaust gas.
 12. The device of claim 9 wherein the passage extends from an ambient port in fluid communication with the ambient gas to an exhaust port in fluid communication with only the bore such that all of the ambient gas is drawn directly into the bore in the baffle wall.
 13. The device of claim 9 further comprising: a plurality of the bores extending through the baffle wall and in fluid communication with the exhaust conduit for directing the flow of exhaust gas through each of the bores and increasing the speed of the flow of exhaust gas through each of the bores; and a plurality of the passages extending through the sidewall of the body from the ambient environment, each of the passages extending to respective bores in the baffle wall for fluid communication therebetween.
 14. The device of claim 13 wherein the plurality of bores and the plurality of passages are symmetrically and radially positioned about the baffle wall and sidewall, respectively.
 15. The device of claim 9 wherein the distal end portion has an outlet in fluid communication with the exhaust conduit and configured for connecting to a remaining portion of the exhaust system.
 16. A method of discharging an exhaust gas from an exhaust system of a motor vehicle into an ambient environment, comprising; blocking a flow of the exhaust gas with a baffle wall in order to direct the gas through a bore in the baffle wall; increasing a speed of the flow of the exhaust gas moving into the bore such that a pressure of the flow of the exhaust gas within the bore is reduced to create a venturi at the bore; and drawing an ambient gas through a passage in a sidewall and into the bore for reducing a temperature of the flow of the exhaust gas.
 17. The method of claim 16 further comprising: generating a desirable exhaust sound when simultaneously directing the flow of the exhaust gas through the bore and drawing ambient gas into the bore via the venturi.
 18. The method of claim 16 further comprising: dividing the flow of the exhaust into a plurality of flows of exhaust gas for mixing ambient gas with the exhaust gas.
 19. The method of claim 16 wherein drawing the ambient gas further comprises: moving the exhaust gas into the bore at an angle between 0 and 90 degrees from a direction of the flow of the exhaust gas. 